Tubing for electric submersible pumps used in oil production

Abstract

A tubing for an electric submersible pump (ESP) for oil production. Cables are wrapped outside a first outer sheath at equal intervals; an inner side of the cable is covered with an insulating layer; an inner side of the insulating layer is covered with an aluminum tape; and a conductor is nested inside the aluminum tape. The inner pipe is combined with the cable to meet the oil production requirement of a coiled tubing (CT) and solve a power transmission problem of the submersible pump. The first outer sheath and a second outer sheath ensure that the tubing has a high bearing capacity and stability inside. A first steel belt and a second steel belt ensure a high resistance to pulling and deformation inside the tubing in use.

What is claimed is: 
     
       1. A tubing for use in combination with an electric submersible pump for oil production, the tubing comprising:
 an inner pipe and a first steel belt spirally wrapped around an exterior surface of the inner pipe; 
 a first outer sheath enclosing each of the inner pipe and the first steel belt; 
 a plurality of cables circumferentially disposed around an exterior surface of the first outer sheath, wherein adjacent cables of the plurality of cables are spaced apart from each other at equal distances, each of the plurality of cables comprising:
 an interior surface enclosing an insulating layer, the insulating layer enclosing an amount of an aluminum tape, the amount of the aluminum tape enclosing a conductor therein; 
 
 a cable sheath enclosing the plurality of cables and a second steel belt spirally wrapped around an exterior surface of the cable sheath; and 
 a second outer sheath enclosing each of the cable sheath and the second steel belt. 
 
     
     
       2. The tubing of  claim 1 , further comprising a steel wire mesh wrapped around an exterior surface of the second outer sheath, and a protective sleeve enclosing the steel wire mesh. 
     
     
       3. The tubing of  claim 2 , further comprising a plurality of wear-resistant strips bonded to an exterior surface of the protective sleeve, wherein adjacent wear-resistant strips of the plurality of wear-resistant strips are spaced apart from each other at equal distances. 
     
     
       4. The tubing of  claim 3 , wherein each of the protective sleeve and the plurality of wear-resistant strips are made of a wear-resistant rubber material. 
     
     
       5. The tubing of  claim 1 , wherein the plurality of cables comprises four cables, wherein three of the conductors are power transmission conductors and one of the conductors is a grounding conductor. 
     
     
       6. A method of coiling a tubing for use in combination with an electric submersible pump for oil production, the method comprising steps of:
 straightening an inner pipe, and enclosing an exterior surface of the inner pipe with a first steel belt; 
 passing the straightened inner pipe and the first steel belt through a die, and, via an extrusion device, extruding a first outer sheath on the exterior surface of the inner pipe and an exterior surface of the first steel belt; 
 cooling the inner pipe, the first steel belt, and the first outer sheath in an amount of water; 
 after cooling, coiling the inner pipe, the first steel belt, and the first outer sheath onto a first spool; 
 enclosing the inner pipe, the first steel belt, and the first outer sheath with a cable sheath via a cable stranding machine; 
 circumferentially disposing a plurality of cables around an exterior surface of the first outer sheath; 
 extruding a second outer sheath around an exterior surface of the plurality of cables and the cable sheath, thereby enclosing the plurality of cables and the cable sheath; 
 via a weaving device, weaving a steel wire mesh around an exterior surface of the second outer sheath; 
 extruding, via a rubber extrusion device, a protective sleeve around an exterior surface of the steel wire mesh to form a final tubing; 
 cooling the final tubing; and 
 coiling the final tubing onto a second spool.